INSECTS. 317 



their wonderful increase, and sometimes •will utterly rout 

 the Aphides in a single week.* 



The remedies advised for the apple tree Aphides, are 

 equally applicable to those of the cherry, and their natural 

 enemies are the same and equally efficacious ; but Aphides 

 have internal foes likewise, that may be named here. The 

 Ichneumon-flies are parasitic, their larvse feed upon the 

 substance of the Aphides. The genus Aphidius is parti- 

 cularly provided to furnish parasites to these insects, in 

 which they deposit a single egg, selecting a louse of the 

 proper size to sustain their progeny : the egg hatches to 

 a larva, which exhausts the Aphis by the time it has at- 

 tained its growth, when the poor creature fastens itself 

 securely to the leaf, and dies, leaving its carcase a secure 

 resting place for the pupa of the Ichneumon. These para- 

 sitic-insects, which feed internally upon the Aphides, are 

 as effective in their destruction as the Aphis-lions, or any 

 other class of their enemies.* * 



Aphis persicae, or the Peach Tree-louse, punctures the 

 leaves of this plant, and Dr. Fitch "j" thinks, is the common 

 though not the only cause of the curl in the peach tree 

 leaves. Our intelligent orchardists have found these in- 

 sects occasionally in the curled leaves of the peach, but do 

 not agree with this distinguished entomologist, in consid- 

 ering them a cause of that malady. 



Aphis vitis !, or the Vine Aphis, is often quite trouble- 

 some on vigorous young shoots of the grape vine, both 

 wild and cultivated, particularly the former. These in- 



• Bept. cU. p. 125. 



•• Bept. cit. p. 131. 



t Trans. N. T. Ag'l Soc., 1856, p. 359. 



